Active-fluidics versus gravity-fluidics in lens extraction: A systematic review and meta-analysis of randomized controlled trials

Abstract

Objective To investigate differences in outcomes between active-fluidics and gravity-fluidics phacoemulsification systems. Methods We searched PubMed, Embase, and Cochrane Library databases for randomized controlled trials (RCTs) published no later than December 1, 2021. The Cochrane Collaboration risk of bias tool was used for quality assessment. We presented the outcomes as standardized mean differences (SMDs) with 95% confidence intervals (CI). Sensitivity analysis was performed by removing studies that included ≥2 types of phacoemulsification tips. Results We analyzed six RCTs that totally enrolled 884 patients. Patients undergoing lens extraction with active-fluidics systems exhibited lower cumulative dissipated energy (CDE), total aspiration time (TAT), and estimated fluid usage (EFU) compared with patients who did not (SMD [95% CI]: CDE, − 0.818 [ − 1.054 to − 0.582]; TAT, − 0.664 [ − 0.850 to − 0.479]; EFU, − 0.655 [ − 0.932 to − 0.378]). A sensitivity analysis revealed similar results for CDE, TAT, and EFU. For endothelial cell density (ECD) 1 week after surgery, ECD 1 month after surgery, and central corneal thickness (CCT) 1 week after surgery, outcomes of both systems were comparable (ECD at 1 week, 0.074 [ − 0.177 to 0.325]; ECD at 1 month, 0.069 [ − 0.167 to 0.305]; CCT 1 week after surgery, 0.077 [ − 0.173 to 0.328]). No severe adverse events in patients treated with either system were reported in the studies. Conclusion Active-fluidics systems are superior to gravity-fluidics systems with respect to CDE, TAT, and EFU; no differences in postoperative ECD and CCT were observed. Future studies are required to determine the reasons for heterogeneity and to detect rare adverse events.